终止 WebClient 和HttpWebRequest

我们在开发sl项目时 通讯用的 是    WebClient  和HttpWebRequest  

有时候 查询量过大  需要终止

 

   CancellationTokenSource cts = new CancellationTokenSource();
            CancellationToken token = cts.Token;
            WebClient wc = new WebClient();
            token.Register(() => wc.CancelAsync());
            //HttpWebRequest  
            // HttpWebRequest request = (HttpWebRequest)WebRequest.Create("");
             //token.Register(() => request.Abort());

            Console.WriteLine("Starting request");
            wc.DownloadStringAsync(new Uri("http://weibo.com/signup/signup.php?inviteCode=2093492691"));
            wc.DownloadStringCompleted += (sender,e) => 
            {
                if (e.Cancelled)
                {

                }
            };
            cts.Cancel();   //通知 取消下载